Wyoming Administrative Code
Agency 020 - Environmental Quality, Dept. of
Sub-Agency 0009 - Solid Waste Management
Chapter 3 - INDUSTRIAL LANDFILL REGULATIONS
Section 3-7 - Design and Construction Standards

Universal Citation: WY Code of Rules 3-7

Current through September 21, 2024

(a) Surveyed corners: All facility boundary corners shall be surveyed and marked with permanent survey caps.

(b) Access roads: Facility access roads shall be constructed to enable use under inclement weather conditions.

(c) Buffer zones: All facilities shall be designed and constructed with a buffer zone that is a minimum of twenty feet wide within the facility perimeter fence.

(d) Cover material: Sufficient cover material shall be available to properly operate the facility through the closure period.

(e) Surface water structures: Surface water structures shall be designed and constructed to:

(i) Prevent flow onto the active portion of the landfill during the peak discharge from a 25-year storm;

(ii) Collect and control run-off from the active portion of the landfill from at least the water volume resulting from a 24-hour, 25-year storm;

(f) Sediment control structures: Sediment control structures shall be designed and constructed in accordance with Chapter 11 of the Water Quality Rules.

(g) Engineered containment system or performance-based design:

(i) The Administrator may require either:
(A) An engineered containment system, including a composite liner, leachate collection system, and final cover with a permeability less than or equal to the permeability of the bottom liner system, in new units and lateral expansions, or

(B) A performance-based design that complies with the requirements set out in W.S. § 35-11-527 and demonstrates that concentrations of pollutants will not exceed groundwater protection standards at the relevant point of compliance established by the Administrator that is no more than 150 meters (492 feet) from the solid waste management unit boundary on land owned, leased, or otherwise controlled by the owner of the landfill under any of the following conditions:
(I) When native soils underlying the landfill are sufficiently permeable to allow potential contamination of groundwater through operation of the facility;

(II) When solid waste types or operation practices create a reasonable potential for contamination of underlying soils or groundwater;

(III) When site hydrologic conditions create a condition whereby groundwater is not sufficiently protected from contamination; or

(IV) At any facility which receives greater than 500 tons of industrial solid waste per operating day, on a monthly average. Containment systems at these facilities shall include leachate collection and leak detection systems.

(h) Engineered containment systems, if required by the Administrator, shall be designed and constructed as specified in Chapter 2, Section 7(g) and (h) of these rules.

(i) Slope stability for excavations: Trench walls shall not exceed a ratio of 1.5:1 (horizontal: vertical) unless a slope stability analysis demonstrates steeper slopes can be safely constructed and maintained. This analysis may be based on site-specific soil stability calculations or Wyoming Occupational Safety and Health Administration regulations for excavations.

(j) Methane control systems for on-site structures: All structures on the facility will be designed to prevent the accumulation of methane such that the concentration of methane gas in facility structures does not exceed 25% of the lower explosive limit for methane.

Disclaimer: These regulations may not be the most recent version. Wyoming may have more current or accurate information. We make no warranties or guarantees about the accuracy, completeness, or adequacy of the information contained on this site or the information linked to on the state site. Please check official sources.
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